1. Field of the Invention
The present invention relates generally to gelled fluids that flow through an orifice in US class 22 subclass 272. Specifically the invention relates to gels that are dispensed through a trigger spray nozzle or aerosol spray valve. Still more specifically, the invention relates to nonaquious gels containing polymers whose instantaneous viscosity decreases when the gel is subjected to shear force. The invention includes spray gel compositions, methods of making spray gels and methods of dispensing gels whose viscosity exhibits an instantaneous temporary decrease in viscosity when the gel flows through an orifice, such as a spray nozzle or aerosol valve.
2. Background Information
Spray gels taught by the prior art are aqueous gels or hydrocarbon water emulsions, such as those used for hairspray and the like. An example is Amphomer LV-71® marketed by National Starch and Chemical, Bridgewater, N.J., which is used in personal care applications such as hair spray, spritzes, spray gels and setting lotions. These prior art aqueous gels must have low viscosity so they may be dispensed at low pressure through a manual trigger pump or at somewhat higher pressure by propellant from a spray can aerosol valve. The prior art also teaches the use of low viscosity hydrocarbon solvents in sprays. Hydrocarbon gels are too thick to use confidently in sprays, especially in low-pressure trigger sprays. These prior art pressure driven sprays are used to dispense a multitude of low viscosity household, cosmetic, personal care and industrial products. Some examples are furniture polish, insecticide, paint, lubricants, skin care products including sun care products or sun tan oils and many others that form an indispensable part of everyone's daily life.
In order to understand and appreciate the present invention, it is necessary to understand the prior art of aerosol spray cans and manual trigger sprays.
Aerosol Spray Cans
The concept of an aerosol sprays from pressurized containers originated as early as 1790, when self-pressurized carbonated beverages were introduced in France. In 1837, a man called Perpigna invented a soda siphon incorporating a valve. In 1899, inventors Helbling and Pertsch patented aerosols pressurized using methyl and ethyl chloride as propellants.
On Nov. 23, 1927, Erik Rotheim of Norway patented the first aerosol can and valve that could hold and dispense products and propellant systems. This was the forerunner of the modern aerosol can and valve.
During World War II, the U.S. government funded research into a portable way for service men to spray malaria-carrying bugs. Two Department of Agriculture researchers, Lyle Goodhue and William Sullivan, developed a small aerosol can to pressurized by a liquefied gas (a fluorocarbon) in 1943. Aerosol spray cans rely on a basic principle of physics: a gas under enough pressure will turn into a liquid, and as pressure is relieved, will expand and turn back into a gas. Simply put, and aerosol spray can is a small container (usually steel or aluminum) containing the product to be dispensed and a propellant (normally an inert gas) to force the product through the valve and out of the can. The valve is the heart of the system. Both the product and the propellant are kept inside the package by the valve.
In 1953, Robert H. Abplanalp patented the first clog-free valve for spray cans. In 1950 he founded Precision Valve Corporation. In its first full year of operation, 15 million valves were produced. In 2001 Precision produced over 4 billion valves at 20 facilities around the world. Abplanalp has patented many improvements on his first aerosol spray valve. A good example of this art, which is incorporated into this application for reference, is disclosed in U.S. Pat. No. 4,396,152 “Aerosol Dispenser System.”
Examples of the products dispensed from aerosol spray cans include: Insecticides: Ant & Roach killers, House & Garden, Flying Insect Killers, Yard Foggers, Personal Insect repellants, Wasp & Hornet Killers and Total Release Foggers. Household Products: Disinfectant Sprays, Fabric Protectors, Spray Starch, Glass Cleaners, Pre-Wash Sprays, Basin, Tub & Tile Spray, Air Fresheners, Oven Cleaners, Rug Cleaners and Furniture Polish. Personal Care Products: Hair Sprays and low VOC Hair Sprays, Mousse, Antiperspirants, Personal Deodorants, Cologne, Foot Sprays, Shave Creams and Gels. Animal Products: Flea & Tick Killers. Auto & Industrial: Waxes, De-Icers, Degreasers, Carb & Choke, Tire Foam Cleaners, Brake Cleaners, Undercoating, Starting Fluids, Cleaners, Silicones, and Tire Inflators.
The aerosol valve specifications from Precision Valve Corporation for some personal care products (see tables below) show that typical product dispersing orifices range in size from about 0.01 to about 0.03 inches.
DISINFECTANT SPRAYVertical ValvesPartStandard ValveU.S. 90 ValveTilt ValveStem04-1210 .013″04-1210 .013″04-7710 2 × .013″Stem05-0310 Buna05-5110 Buna05-0710 BunaGasket06-6010 S/S06-6010 S/S06-7050 S/SSpring07-1901 .080″07-5380 .080″07-1901 .080″Housing09-201009-201009-2010Dip Tube32-8300*; 42-8180***32-8300*; 42-8180***32-8300*; 42-8180***MountingFlair 01-5848 .020Flair 01-5848 020″Delta Tilt 21-7221 .013″CupMBST ShortMBST ShortMB AquaActuatorsKosmos 21-8121 .013″Kosmos 21-8121 .013″Touchdown Tilt 21-7021 .013″MB AquaMB AquaMB AquaDelta 21-4721 .013″Delta 21-4721 .013″MB AquaMB AquaBOF 21-8521 .013″BOF 21-8521 .013″MB AquaMB Aqua(*) (**) (***) See below
FABRIC PROTECTORVertical ValvesPartStandard ValveU.S. 90 ValveTilt ValveStem04-1220 .018″04-1220 .018″04-7740 2 × .080″Stem Gasket05-0310 Buna05-5110 Buna05-0710 BunaSpring06-6010 S/S06-6010 S/S06-7050 S/SHousing07-1901 .080″07-5380 .080″07-1901 .080″Dip Tube09-201009-201009-2010Mounting Cup32-8300*; 42-8180***32-3000**; 42-32-8300*; 42-8180***ActuatorsBOF 21-8526 .025″8180***Delta Tilt 21-7226 .025″MB AquaBOF 21-8526MB AquaKosmos 21-8126 .025″.025″Touchdown Tilt 21-7026 .025″MB AquaMB AquaMB AquaDelta 21-4726 .025″Kosmos 21-8126MB Aqua.025″ MB AquaDelta 21-4726.025″MB Aqua*Conical cup; Epon T/B; Dimpled; PE Sleeve**Hi-Load cup; Epon T/B; Dimpled; PE Sleeve***Hi-Load cup; Epon Top; Laminate Bottom; Dimpled
SPRAY STARCHVertical ValvesPartStandard ValveU.S. 90 ValveTilt ValveStem04-1270 2 × .020″04-1270 2 × .020″04-7740 2 × .020″Stem Gasket05-0310 Buna05-5110 Buna05-0710 BunaSpring06-6010 S/S06-6010 S/S06-7050 S/SHousing07-1901 .080″07-8380 .080″07-1901 .080″Dip Tube09-201009-201009-2010Mounting Cup32-8300*; 42-8180***32-3000**; 42-8180***32-8300*; 42-8180***ActuatorsFlair 01-5848 020″Flair 01-5840 .020″Delta Tilt 21-7223 .020″MBSTMBSTMB ConcaveKosmos 21-8123 .020″Kosmos 21-8123 .020″Touchdown Tilt 21-7023MB AquaMB Aqua.020″ MB AquaDelta 21-4723 .020″Delta 21-4723 .020″MB AquaMB Aqua(*) (**) (***) See Below
GLASS CLEANERPartStandard ValveU.S. 90 ValveTilt ValveStem04-1270 2 × .020″04-1270 2 × .020″04-7740 2 × .020″Stem Gasket05-0310 Buna05-5110 Buna05-0710 BunaSpring06-6010 S/S06-6010 S/S06-7050 S/SHousing07-1901 .080″07-5380 .080″07-1901 .080″Dip Tube09-201009-201009-2010Mounting Cup32-8300*; 42-32-3000**; 42-32-8300*; 42-8180***Actuators8180**8180***Delta Tilt 21-7226 .025″BOF 21-8526 .025″BOF 21-8526 .025″MB AquaMB AquaMB AquaTouchdown Tilt 21-7026 .025″Kosmos 21-8126Kosmos 21-8126MB Aqua.025″.025″MB AquaMB AquaDelta 21-4726Delta 21-4726.025″.025″MB AquaMB AquaFlair 01-5840Flair 01-5840.020″.020″MBSTMBST*Conical cup; Epon T/B; Dimpled; PE Sleeve**Hi-Load cup; Epon T/B; Dimpled; PE Sleeve***Hi-Load cup; Epon Top; Laminated Bottom; Dimpled
BASIN, TUB & TILE CLEANERVertical ValvesPartVertical ValveTilt ValveStem04-1270 2 × .020″04-7740 2 × .020″Stem05-0310 Buna05-0710 BunaGasketSpring06-6010 S/S06-7050 S/SHousing27-6508 .040″ Up/Down27-6508 .040″ Up/DownDip Tube09-5310 Large09-5310 LargeMounting32-8380*; 42-8180***32-3080**; 42-8180***CupActuatorsFlair 01-5840 .020″ MBSTDelta Tilt 21-7226 .025″Kosmos 21-8126 .025″ MB AquaMB AquaDelta 21-4726 .025″ MB AquaTouchdownTilt 21-7126 .025″BOF 21-8526 .025″ MB AquaMB Aqua*Conical cup; Epon Top; Uncoated Bottom; Dimpled; PE Sleeve**Conical cup; Epon Top; Uncoated Bottom; Dimpled; PE Sleeve***Hi-Load cup; Epon Top; Laminate Bottom; Dimpled
PRE-WASHVertical ValvesPartStandard ValveU.S. 90 ValveTilt ValveStem04-1270 2 × .020″04-1270 2 × .020″04-7740 2 × .020″Stem Gasket05-0310 Buna05-5110 Buna05-0710 BunaSpring06-6010 S/S06-6010 S/S06-7050 S/SHousing07-1901 .080″07-5380 .080″07-1901 .080″Dip Tube09-201009-201009-2010Mounting Cup32-8300*; 42-8180***32-3000**; 42-8180***32-8300*; 42-8180***ActuatorsFlair 01-5861 .025″Flair 01-5861 .025″Delta Tilt 21-7223 .020″MBFTMBFTMB AquaKosmos 21-2186 .025″Kosmos 21-8126 .025″Touchdown Tilt 21-7023 .020″MB AquaMB AquaMB AquaBOF 01-8525 .025″BOF 01-8526 .025″MB AquaMB Aqua*Conical cup; Epon T/B; Dimpled: PE Sleeve**Hi-Load cup; Epon T/B; Dimpled; PE Sleeve***Hi-Load cup; Epon Top; Laminate Bottom; Dimpled
AIR FRESHENERVertical ValvesPartStandard ValveU.S. 90 ValveStem04-1270 2 × .020″04-1270 2 × .020″Stem Gasket05-0330 Neo05-5130 NeoSpring06-6010 S/S06-6010 S/SHousing04-3415 .062 × .020″ VT Capillary07-3894 .050″ × .020″ VT CapillaryDip Tube09-3530 .060″ Capillary09-3530 .060″ CapillaryMounting Cup32-8300*; 42-8180***32-3000**; 42-8180***ActuatorsNeptune Dome 03-1062 .025″03-0550 .023″ ST/FT SBUMB Aqua (for 205 N/I Can)(For 202 Straight Side)03-0550 .023″ S/TFT SBU(For 202 Straight Side)*Conical cup; Epon T/B; Dimpled: PE Sleeve**Hi-Load cup; Epon T/B; Dimpled; PE Sleeve***Hi-Load cup; Epon Top; Laminate Bottom; Dimpled
OVEN CLEANERVertical ValvesPartStandard ValveU.S. 90 ValveStem04-1240 .024″04-1240 .024″Stem Gasket05-0310 Buna05-5110 BunaSpring06-6010 S/S06-6010 S/SHousing07-1901 .080″07-5380 .080″Dip Tube09-201009-2010Mounting Cup32-8380*32-3080**ActuatorsAlpha 01-5972 .030″Alpha 01-5972 .030″MBFT RSMBFT RS*Conical cup; Epon Top; Uncoated Bottom; Dimpled: PE Sleeve**Hi-Load cup; Epon Top; Uncoated Bottom; Dimpled; PE Sleeve
RUG CLEANERVertical ValvesPartVertical ValveStem04-1248 4 × .024″Stem Gasket05-0310 Buna or 0410 Hex BunaSpring06-6010 S/SHousing07-6937 Inverted W/TailpieceDip TubeNoneMounting Cup32-8300*Actuators01-3596 .013″ × .040″Vertical*Conical cup; Epon T/B; Dimpled: PE Sleeve
FURNITURE POLISHVertical ValvesPartStandard ValveU.S. 90 ValveTilt ValveStem04-1270 2 × .020″04-1270 2 × .020″04-1270 2 × .020″Stem Gasket05-0310 Buna05-5110 Buna05-0710 BunaSpring06-6010 S/S06-6010 S/S06-7050 S/SHousing07-1901 .080″07-5380 .080″07-1901 .080″Dip Tube09-201009-201009-2010Mounting Cup32-8300*; 42-8180***32-3000**; 42-8180***32-8300″; 42-8180***ActuatorsFlair 01-5840 .020″Flair 01-5840 .020″Delta Tilt 21-7223 .020″MBSTMBSTMB AquaDelta 21-4726 .025″Delta 21-4726 .025″Touchdown Tilt 21-7023MB AquaMB Aqua.020″ MB AquaKosmos 21-8126 .025″Kosmos 21-8126 .025″MB AquaMB AquaBOF 21-8526 .025″BOF 21-8526 .025″MB AquaMB Aqua*Conical cup; Epon T/B; Dimpled: PE Sleeve**Hi-Load cup; Epon T/B; Dimpled; PE Sleeve***Hi-Load cup; Epon Top; Laminate Bottom; Dimpled
Manual Trigger Sprays:
In 1958 Tetsuya Tada of Tokyo, Japan, invented the manual trigger spray. Tada founded Canyon Corporation, Tokyo, which supplies consumer and industrial trigger sprays worldwide. Two good examples of manual trigger sprays, which are incorporated into this application for reference, are disclosed in Tada's U.S. Pat. No. 3,701,478 “Hand Sprayer” and U.S. Pat. No. 4,153,203 “Trigger Type Sprayer.”
Manual trigger sprays are an extremely useful type of machine and an excellent demonstration of basic plumbing principles. A spray-bottle head is made up of only a few parts. It has a trigger lever, which activates a small pump. This pump is attached to a plastic tube that draws cleaning fluid from the bottom of the reservoir. The pump forces this liquid down a narrow barrel and out a small hole at the gun's muzzle. The hole, or nozzle, serves to focus the flowing liquid so that it forms a concentrated stream.
The only complex element in this design is the fluid pump, and it's about as simple as they come. The main moving element is a piston, housed inside a cylinder. Inside the cylinder, there is a small spring. To operate the pump, you pull the trigger back, pushing the piston into the cylinder. The moving piston compresses the spring, so when you release the trigger, the piston is pushed back out of the cylinder. These two strokes of the piston, into the cylinder and out again, constitute the entire pump cycle.
The downstroke, the piston pushing in, shrinks the area of the cylinder, forcing fluid out of the pump. The upstroke, the spring pushing the piston back out, expands the cylinder area, sucking fluid into the pump. In a spray bottle, you need to suck cleaning fluid in from the reservoir below and force it out through the barrel above. In order to get all of the fluid moving through the barrel, the pump must only force the fluid up—it cannot force the fluid back into the reservoir. In other words, the fluid must move through the pump in only one direction.
The device that makes this possible is called a one-way valve. A spray bottle has two one-way valves in the pumping system: one between the pump and the reservoir and one between the pump and the nozzle. Typically, the valve between the pump and the reservoir consists of a tiny rubber ball that rests neatly inside a small seal. The sides of the seal are angled so that the ball won't fall through. Depending on the design, either gravity or a small spring holds this ball against the seal so that the water passageway is blocked off when you are not pumping. When the piston moves out (when you release the trigger), the expanding area of the cylinder sucks on the fluid below, pulling the ball up out of the seal. Since the ball is lifted up, fluid is free to flow from the reservoir. But when you squeeze the trigger, the outward force of the moving fluid pushes the ball into the seal, blocking off the passageway to the reservoir. Consequently, the pressurized fluid is pushed only into the barrel.
In the spray mechanism, the one-way valve between the pump and the nozzle is a sort of cup, which fits over the end of the barrel. On the upstroke, the inward pressure from the pump pulls the cup against the barrel, so air can't flow in through the nozzle. On the downstroke, the fluid pushing out lifts the cup off the barrel slightly and flows on through the nozzle. Without this second one-way valve, the pump system wouldn't be able to draw fluid up from the reservoir because there would be no suction (no drop in air pressure). The upstroke wouldn't lower the air pressure in the pump; it would only draw in more air to maintain that pressure.
This valve also works as a shut-off system. When you screw the nozzle piece in, it pushes the valve cup tightly against the barrel, so you can't force any liquid out. When you loosen the nozzle piece, there is enough room for the valve cup to move back and forth. When you use a spray bottle for the first time, you have to squeeze the trigger a couple of times to spray any fluid. There are two things causing this delay:                Before you start pumping, the gun is set for a downstroke, not an upstroke (the piston is sitting outside the cylinder). When you first pull the trigger back, and the piston pushes in, there is no liquid to pump out; there is only air in the cylinder chamber. The piston has to slide out to suck any fluid from the reservoir.        On this first upstroke, the pump starts sucking the cleaning liquid from the reservoir. But it also sucks in any air sitting in the plastic tube leading to the reservoir. Before you can start spraying the cleaning liquid, you have to drive this air through the pump mechanism. This may take a couple of downstrokes and upstrokes.        
This simple pump design, called a reciprocating piston pump, is used for a variety of tasks. In addition to pressurizing water, air and many other fluids, this design can also extract water and oil from underground. We even have reciprocating pumps built into our bodies: Your heart expands to draw low-pressure blood in through one one-way valve and contracts to force high-pressure blood through another one-way valve, back into your body. The same basic mechanism that makes an ordinary spray bottle work also serves to keep you alive!
Examples of consumer and industrial manual spray trigger pump specifications, from the Canyon Corporation are:
Nozzle orifice□ 0.6 mmSpray output per0.7 gram ± 0.1 gram (Using distilled water)stroke1.0 gram ± 0.1 gram (Using distilled water)Spray pattern□ 180 mm ± 40 mm (At distance of 200 mm)Spray Angle38.6°~57.6°DurabilityMore than 10,000 continuous trigger pulls. (Water.)Weight25.1 gram ± 1.5 gram (LB = 150 mm)
Example of industrial spray trigger pump specifications:
Nozzle orifice□ 0.6 mmSpray output per2.4 gram ± 0.45 gram (Using distilled pure water)strokeSpray pattern□ 200 mm ± 30 mm (At distance of 100 mm)Spray Angle0°~90°DurabilityMore than 50,000 continuous trigger pulls. (Water.)Weight76 gram ± 1.5 gram (LB = 230 mm)
The nozzle orifice of these trigger pumps is 0.60 mm, which is 0.023 inches. It should be noted that this is about the same diameter as the nozzle orifices of the aerosol pressure valves described above. However, trigger spray valves operate at lower pressure than aerosol can valves, thus low dispensed product viscosity is even more necessary to the proper operation of these hand actuated sprayers. In addition to being forced through this small nozzle aperture, the dispensed product must pass through the moving parts of the pump including the ball valve, which may have even smaller working clearances.
In order to spray moderately viscous gel-type hair-conditioning compositions, the gel must be a thin aqueous solution or must be a dilute hydrocarbon water emulsion. An example is disclosed in U.S. Pat. No. 5,340,570, which teaches incorporation of an alkyl polyol and a water soluble or emulsifiable silicone based compound into the gel, in a 95% water solution to obtain a satisfactory liquefied spray mist through a pump nozzle having apertures ranging between about 0.01 and 0.03 mm.
The prior art teaches the addition of diblock and triblock polymers to increase viscosity of a gel composition. An example of this is disclosed in U.S. Pat. No. 6,451,299 B1 “Synergisic Effect on Viscosity Between Associative Polymers.”
Child resistant packaging of product containing low viscosity hydrocarbons:
Effective Oct. 25, 2002 the Consumer Product Safety Commission adopted final Rules on Household Products Containing Hydrocarbons. (Federal Register: Oct. 25, 2001 (Volume 66, Number 207)][Rules and Regulations][Page 53951-53957] 16 CFR 1700.
Promulgated under authority of the Poison Prevention Packaging Act (PPPA), these new rules require child-resistant (CR) packaging for certain products that contain low-viscosity hydrocarbons. This requirement is intended to protect children under five years of age from serious injury associated with aspiration of hydrocarbon products. The requirement applies to certain prepackaged nonemulsion-type liquid household chemical products, including drugs and cosmetics, that contain ten (10) percent or more hydrocarbons by weight and have a viscosity of less than one hundred (100) Saybolt Universal Seconds (SUS) at 100 deg. F. For purposes of these rules, hydrocarbons are defined as compounds that consist solely of carbon and hydrogen. For a product that contains multiple hydrocarbons, the total percentage of hydrocarbons in the product is the sum of the percentages by weight of the individual hydrocarbon components.
Saybolt Universal second (SUS) is a unit of kinematic viscosity given by readings on Saybolt viscometers. The Saybolt Universal viscometer is used for liquids having viscosities below 1000 centistokes (or 10 stokes. Saybolt seconds are considered obsolete, but they have been used traditionally in the petroleum industry and are common in technical articles. A “Stoke” (St) is a unit of kinematic viscosity (cm2 s−1). The SI unit of kinematic viscosity is m2 s−1 (=10000 stoke).
Direct aspiration into the lung, or aspiration during vomiting, of small amounts of petroleum distillates and other similar hydrocarbon solvents can result in chemical pneumonia, pulmonary damage, and death. These chemicals are the primary ingredients in a multitude of consumer products to which children have access. The viscosity of a hydrocarbon-containing product contributes to its potential toxicity. Viscosity is the measurement of the ability of a liquid to flow. Liquids with high viscosities are thick or “syrupy.” Liquids with low viscosities are more “watery.” Products with low viscosity pose a greater risk of aspiration into the lungs. Under regulations issued pursuant to the Federal Hazardous Substances Act (FHSA), 15. U.S.C. 1261-1278, the CPSC regulates the labeling of hazardous household substances containing 10 percent or more by weight of petroleum distillate hydrocarbons because these products may cause injury or illness if ingested. 16 CFR 1500.14. The PPPA regulations in effect as of this date also require child-resistant packaging for certain household products containing petroleum distillates. 16 CFR 1700.14. Under these regulations, the specified consumer products containing 10 percent or more by weight of petroleum distillates, and having viscosities less than 100 Saybolt Universal Seconds (SUS) at 100 deg. F., are subject to child-resistant packaging standards. These PPPA-regulated products include prepackaged liquid kindling and illuminating preparations (e.g., lighter fluid) (16 CFR 1700.14(a)(7)), prepackaged solvents for paint or other similar surface-coating materials (e.g., paint thinners)(16 CFR 1700.14(a)(15)), and nonemulsion liquid furniture polish (16 CFR 1700.14(a)(2)).
Many household substances contain more than ten percent hydrocarbons and have viscosities below 100 SUS at 100 deg. F. The low viscosity is desirable so these products may be dispensed through an pressurized aerosol spray valve or a manual trigger spray. A good example is spray furniture polish. Under these new rules, the manual trigger spray containing these products must be equipped with child resistant caps, which are expensive. Alternatively the product may be modified to have a viscosity over 100 SUS, but the higher viscosity product does not flow well through a trigger spray or aerosol spray valve.